Designing And Health Simulation For The Control System Of A Solid Ducted Rocket

A solid ducted rocket is an optimal propulsion device for the new generation of aircraft in aerospace,it possessing the advantages of high specific impulse,long range,low weight,compact structure,easy storage and so on.With the development of solid ducted rocket,the engine control system plays a more and more role in improving the performance and enrich the function of the solid ducted rocket.In this thesis,the designing method and engineering application of ducted rocket control system are proposed,and the component health modeling and health simulation of this system is carried out.The main research work include following:Firstly,the research is carried out in a certain type of solid ducted rocket,the modeling and response characteristics analysis of key components such as gas generator,flow regulating motor and flow regulating device are proposed.According to the difference between the response of the classical dynamic model of gas generator and the test data,the correlation analysis of the parameter deviation is given,and the deviation is approximately equivalent to the free volume correction parameters,and the general form of the virtual free volume correction model is carried out.Based on a large number of experimental data,the optimal correction parameters are obtained,and the possible physical explanation of the deviation is analyzed.Secondly,the control characteristics of solid ducted rocket are studied.The load characteristics of the flow regulating device are deeply explored based on test data,the load is related to the gas generator pressure and the impact area of the regulator valve.The load model of flow regulation device is established based on Stribeck friction model,because the flow regulating device cannot provide the low-speed uniform excitation environment for parameter identification of Stribeck model,the multi parameter dynamic identification method based on the general form of rotational dynamics is studied by using genetic algorithm,and the feasibility and effectiveness of the method are verified by simulation.The hysteresis model is used to carry out the modelling of the backlash,and the negative influence of the backlash characteristics on the ducted rocket control system is analyzed.According to the characteristic parameters of linear model of solid ducted rocket,the influence of working pressure and free volume is analyzed,and the control characteristics under the condition of variable parameters are studied.Through the experimental phenomena,the negative regulation characteristics of gas flow are summarized,and the causes of negative regulation and the influence of negative regulation on the design of engine control system are analyzed.Thirdly,the control method of solid ducted rocket is studied,and the design framework of engine control system is constructed.According to the negative regulation constraint and backlash characteristics,the control law of pressure control loop is studied;the RBF-BP variable parameter controller based on working pressure and free volume is designed,which can ensure the stability of the control system and effectively improve the control quality of the system under the condition of parameter changes;In order to solve the influence of clearance on engine control fundamentally,and to deal with the two major challenges of gap compensation control: less available information and uncertain clearance state,an adaptive gap compensation control method based on touch state observation is proposed.Then,the research of health modeling and simulation for solid ducted rocket control system is carried out.The health problems of ablation and deposition of flow control device are analyzed,and the accumulation and collapse model of deposition is constructed by the method of characteristic time.Through health simulation,the health phenomenon in the process of engine test is reproduced to a certain extent,and the influence of health mode of valve configuration change on control system is further analyzed.A tube blocked health model of pressure measuring unit is analyzed,the health model of tube blocked is constructed based on the inflation / deflation process of a fixed volume chamber.The influence of different health degree of tube blocked on pressure measurement response is given,and the health simulation is used to reproduce the phenomenon of tube blocked in the process of engine test,which has high reliability.In view of the long-term storage requirements of solid ducted rocket,the health problems of propellant parameter bias and sensor measurement zero offset caused by component aging are analyzed,and the influence of aging problems on engine control system is also discussed.Finally,a HIL simulation platform is designed to test and evaluate the ducted rocket control system.The platform can bring the key components hardware of the control system into the simulation loop,and flexibly configure the health parameters and model parameters to carry out a variety of simulation tests.Based on the platform,the experiments under multi working conditions are given,and the adaptability and robustness of the engine control system are verified.